Inches to CM Converter

Convert inches to centimeters instantly, with a reference table covering screen sizes, waist measurements and hardware dimensions.

Inches

Centimeters

1 in = 2.54 cm

Multiply inches by 2.54 to get centimeters.

The link carries the values you entered, so whoever opens it sees the same result. Nothing is stored on our side — the numbers travel in the link itself.

Inches to centimeters reference table

The conversions people look up most often, rounded to 2 decimal places.

Common inches to centimeters conversions
Inch (in)	Centimeter (cm)
1 in	2.54 cm
2 in	5.08 cm
3 in	7.62 cm
6 in	15.24 cm
10 in	25.4 cm
12 in	30.48 cm
15 in	38.1 cm
24 in	60.96 cm
27 in	68.58 cm
32 in	81.28 cm
36 in	91.44 cm
48 in	121.92 cm
60 in	152.4 cm

The inches people look up most

0.5 in = 1.27 cm: Half an inch. Worth knowing because a 13 mm socket fits it loosely enough to round off the bolt head.
6 in = 15.24 cm: A common pipe and timber trade size - though trade sizes are nominal, so measure the real thing.
12 in = 30.48 cm: A foot, and the length of the ruler the metric 30 cm one replaced.
27 in = 68.58 cm: A monitor, measured diagonally rather than across. The panel itself is about 60 cm wide, which is what matters for a desk.
32 in = 81.28 cm: A US waist size. European labels round the result to 81 or 82.

How the inches to cm calculation works

An inch is exactly 2.54 centimeters, so the conversion is one multiplication:

centimeters = inches × 2.54

Nothing is rounded in that factor. The 1959 international yard and pound agreement defined the inch in metric terms rather than the other way round, which is why every inch-to-cm result is exact to as many decimal places as you care to take it.

Most people arrive here from an American spec sheet. Three cases come up constantly:

Screen sizes. A "27-inch" monitor is measured diagonally, not across, so 27 × 2.54 = 68.58 cm describes the diagonal only. A 16:9 panel that size is about 59.8 cm wide — check the width before assuming it fits a shelf.

Clothing. US waist sizes are in inches. A 32 is 32 × 2.54 = 81.28 cm, which European labels round to 81 or 82. A 34 is 86.36 cm.

Hardware. A 12-inch subfloor spacing is 30.48 cm; a 6-inch pipe is 15.24 cm. Trade sizes are often nominal rather than actual, so convert the stated figure and then check the real dimension.

Two things worth knowing:

For a rough figure, multiply by 2.5 and add 2%. 32 inches → 80 → 81.6, against a true 81.28. Close enough to sanity-check a result you have typed in a hurry.
Fractional inches are still common in the US. A ½ inch is 1.27 cm and a ¼ inch is 0.635 cm, so enter 6.5 rather than "6 1/2".

To convert back, divide centimeters by 2.54 — or flip the converter above.

Frequently asked questions

What does the inch in a 6-inch pipe actually measure?

Not the pipe. Up to size 12, nominal pipe size is a label rather than a dimension: NPS 6 steel pipe has an outside diameter of 6.625 inches, or 168.3 mm, and the bore depends on the wall thickness ordered. From NPS 14 upwards the number finally is the outside diameter. Convert the figure from the specification sheet, never the size in the product name.

Why is a two-by-four not 50.8 by 101.6 mm?

Because the timber is planed after it is sawn. A US two-by-four finishes at 1.5 by 3.5 inches, which is 38 by 89 mm, and British planed softwood is sold the same way - the nominal figure describes the rough size before machining. Converting the name rather than the board leaves you about 13 mm over on each dimension, which is a visible gap in a frame.

Why does a US mattress size not match a European one after converting?

Because each market standardised on its own sizes rather than on a conversion. A US queen is 60 by 80 inches, or 152 by 203 cm; a UK king is 150 by 200 cm and a continental European king 180 by 200 cm. None of them lands on another once converted, which is why bedding bought abroad so often nearly fits. Convert the mattress you own and compare it against the local chart.

Inches to CM Converter